This invention relates to an adjusting instrument for electrically adjusting the interior mirror of a motor vehicle about two mutually perpendicular axes, said instrument comprising:
(1) a vehicle-connectable suspension device for a mirror mounting plate and
(2) a mirror mounting plate connected thereto and adjustable about two mutually perpendicular axes, said plate supporting a rearview mirror.
The interior mirrors known at the present time comprise a mirror mounting plate on whose rear side there is provided a suspension device, which together with a ball fixedly connected to the vehicle, forms a universal pivot joint. The suspension device is fixedly clamped onto said ball, so that a high degree of friction is produced between the suspension device and the ball, ensuring that the interior mirror is suspended vibrationless. Naturally, this high friction also entails strong adjusting forces. Since the interior mirror is adjusted manually, this is not a drawback. Relatively strong forces can be exerted during manual adjustment.
It is becoming more and more standard practice to provide the side mirrors of a motor vehicle with an electric adjusting instrument, especially since the outside mirrors are difficult to reach by the driver. The adjusting instrument for outside mirrors can be secured in a mirror housing provided on either side of the motor vehicle. Advantageously, electrically adjustable side mirrors have the possibility of being brought to a number of pre-programmed positions, adjusted to the size, or the posture behind the wheel of different drivers of one and the same motor vehicle.
It is desirable for interior mirrors as well to be placed in some pre-programmed positions, which requires an electrical adjusting instrument. The adjusting instruments used for outside mirrors cannot be used for this purpose, since interior mirros do not have a housing in which an adjusting device can be mounted. The adjusting instrument should, moreover, have a very compact form, since it must not project outside the mirror, and in particular, vertically. The adjusting forces for the mirror to be generated by adjusting motors are considerably weaker than adjusting forces that can be exerted manually on the mirror, so that a low-friction suspension structure has to be chosen. Reduction of the friction in the suspension structure considerably increases the chance of inconvenient vibrations of the interior mirror.